A valve with a bolt or stem that may be mechanically actuated to two different positions by rotary or linear motion. in the first position, the valve disk is located and locked against the seat permitting no fluid flow through the valve. in the second position, one side of the valve disk is located against the seat permitting movement of the disk in a manner that will allow a flow of fluid in one direction through the valve. the valve disk may be spring loaded. it may be inline or cartridge (manifold) design. see also valve (1), lift-check and valve (1), stop-lift-check.